If you attach windows debugger to a .Net framework application, occasionally you may see debug spew of unknown exception 0xe0434f4e.
(cfc.1244): Unknown exception - code e0434f4e (first chance)
0xe0434f4e is defined as EXCEPTION_HIJACK.
(Copied from Rotor 2.0 sources corexcep.h)
#define EXCEPTION_HIJACK 0xe0434f4e // 0xe0000000 | 'COM'+1
EXCEPTION_HIJACK is thrown by CLR as part of the process of suspending threads for garbage collection. It's raised to help resume execution after a suspension.
来自：http://blogs.msdn.com/junfeng/archive/2007/07/16/unknown-exception-0xe0434f4e.aspx